Yeah, it's on my list. When you're scanning sites with high volume (Reddit has ~300 posts per second, Bluesky has ~100) you have to keep things fast and cheap, so I think keywords still have a role, but I think they can become an implementation detail.
My plan over the next couple of months is to build the option for users to enter the kind of things they want to scan for, have AI convert that to keywords, use the keywords for the (fast) scanning, and then apply additional filtering using AI to the small number of posts that match.
Not built yet, but I think there's a bunch of promise to using AI to find relevant conversations online.
Re: APIs, yep, all APIs. I'm not doing any web scraping at the moment